Clean, fresh air and water, free from pollutants, microbes and irritants is an important health concern for many people with compromised immune systems or those suffering from asthma, allergies, and other respiratory disorders or sensitivities. Outdoor air and water pollutants from car emissions, smog, transit systems, and industrial smoke create hazardous health concerns. More critically, indoor air quality poses a threat to health, especially those persons confined to hospitals, clinics, office buildings and transportation systems. For example, bacteria or microscopic particles carrying toxic substances may evade the body's air and fluid filtration systems allowing such toxic microbes or particles to penetrate deep into lung tissue resulting in absorption into the body of possibly toxic contaminants.
Indoor gaseous pollutants may also be a major risk factor to respiratory health. For example, volatile organic compounds (VOCs) are gases that are dispersed from plants, animals, microbes, fungi (molds), as well as in common cleaning solutions, paints, resins, synthetic fibers, and carpets. Building materials such as adhesives, paints, wall boards and ceiling tiles slowly emit the VOC, formaldehyde, which irritates mucous membranes compromising the immune system and exacerbating allergic reactions. Many VOCs such as benzene, are known carcinogens. In fact, studies have shown that prolonged exposure of VOCs in an indoor environment is related to an increase in the incidence of leukemia and lymphoma. Most indoor contaminants include not only VOCs but also organic materials such as dust mites, pet dander, bacteria, viruses, and fungi (mold). Fluid filtration systems have been developed for use in households, hospitals, or transportation systems. However, these systems merely trap these toxic particles and gases rather than destroy or deactivate the contaminants.